Dietary Phytoadditives Enhance Growth Performance, Digestive Enzyme Activity, Antioxidant Status, Immune Gene Expression, and Vibrio parahaemolyticus Resistance in Pacific White Shrimp (

The present study evaluated the effects of dietary phytoadditive supplementation on growth, nutrient utilization, physiological responses, and disease resistance against Vibrio parahaemolyticus in Pacific white shrimp ( Penaeus vannamei ). Four diets, isonitrogenous, isolipidic, and isocaloric, included phytoadditives (turmeric, garlic, ginger, and tamarind in 0.25:0.25:0.25:0.25 ratio) at 0% (control), 0.5%, 1%, and 1.5%. Juvenile shrimp with an initial mean weight of 1.57 ± 0.03 g were randomly placed into 16 tanks. Each tank contained 500 L of water and 50 shrimp. Each treatment diet was allocated to four replicate tanks ( n  = 4). The shrimp were fed four times daily at 06.00, 10.00, 14.00, and 18.00 H for 60 days. At the end of the feeding trial, dietary supplementation with the combined phytoadditives significantly improved the growth performance and nutrient utilization of P. vannamei . Shrimp fed the 1% combined phytoadditives had higher ( p < 0.05) weight gain (16.14 ± 0.32 g), specific growth rate (4.03 ± 0.06% day ⁻¹ ), and protein and lipid efficiency ratios (1.79 ± 0.05 and 12.10 ± 0.37) than those fed the other diets, with a correspondingly lower feed conversion ratio (1.53 ± 0.05). However, the combined phytoadditives did not significantly affect the whole‐body nutrient composition of P. vannamei . Shrimp fed the 1% combined phytoadditive diet showed significantly ( p < 0.05) higher protease (23.02 ± 1.85 U/mg protein % over control) and lipase (18.13 ± 1.52 U/mg protein) activities in the intestine and amylase activity (2.78 ± 0.21 U/mg protein) in the hepatopancreas. Conversely, intestinal amylase, hepatopancreatic protease, and lipase activities were not significantly influenced by the different inclusion levels of the combined phytoadditives. Shrimp fed the 1% combined phytoadditive diet showed significantly higher ( p < 0.05) superoxide dismutase (SOD) (29.43 ± 2.52 U/mg protein) and glutathione peroxidase (GPx) (0.009 ± 0.001 U/mg protein) activities in the intestine and catalase (CAT) activity (1.30 ± 0.22 U/mg protein) in the hepatopancreas. In contrast, CAT activity in the shrimp intestine and SOD and GPx activities in the hepatopancreas were not significantly affected by the dietary treatments ( p > 0.05). Significantly upregulated Toll‐like receptor (TLR), immune deficiency (IMD), and lysozyme (LYZ) relative mRNA expression was observed in shrimp fed a diet supplemented with 1% combined phytoadditives. Dietary supplementation with 1% combined phytoadditives significantly reduced cumulative mortality during the challenge study (28.12 ± 6.25% versus 53.12 ± 6.25% in the control), corresponding to a relative percent survival (RPS) of 47.1%, compared with 17.6% and 38.9% at the 0.5% and 1.5% inclusion levels, respectively. In conclusion, dietary supplementation with 1% combined phytoadditives improved overall growth performance and immune response in Pacific white shrimp.